Buggy code:
public class GET extends Operator implements Evaluable , Query { public static final GET _ = new GET ( ) ; private GET ( ) { } TraversalDescription td = Traversal . description ( ) . depthFirst ( ) . uniqueness ( RELATIONSHIP_PATH ) ; private static TraversalDescription td_eval_IS = Traversal . description ( ) . breadthFirst ( ) . relationships ( IS . _ , Direction . OUTGOING ) ; private static TraversalDescription td_eval_ic = Traversal . description ( ) . breadthFirst ( ) . relationships ( IS . _ , Direction . OUTGOING ) . relationships ( IC . _ , Direction . OUTGOING ) ; public OnQuestion onCalcQuestion ( ) { } private OnQuestion question = new OnQuestion ( ) { @ Override public void onMessage ( final PFlow pf ) { } } ; public Set < Relationship [ ] > get ( PFlow pf , Relationship ref , final String name ) { } public Set < Relationship [ ] > get ( PFlow pf , Node ref , final String name ) { } public Set < Relationship [ ] > get ( PFlow pf , List < Relationship > REFs , final String name ) { Set < Relationship [ ] > set = new javolution . util . FastSet < Relationship [ ] > ( ) ; List < Relationship > nextREFs = new javolution . util . FastList < Relationship > ( ) ; nextREFs . addAll ( REFs ) ; Relationship have = null ; boolean first = true ; while ( true ) { for ( Relationship n : nextREFs ) { System . out . println ( ( "checking<seq2seq4repair_space>" + n ) ) ; have = searchForHAVE ( n , name ) ; if ( ( have != null ) && ( ! ( pf . isInStack ( have ) ) ) ) set . add ( new Relationship [ ] { n , have } ) ; } if ( ( set . size ( ) ) > 0 ) return set ; List < Relationship > newREFs = new javolution . util . FastList < Relationship > ( ) ; for ( Relationship n : nextREFs ) { System . out . println ( ( "" + n ) ) ; System . out . println ( "getStartNode<seq2seq4repair_space>OUTGOING" ) ; if ( first || ( ! ( REFs . contains ( n ) ) ) ) { for ( Relationship r : n . getStartNode ( ) . getRelationships ( Direction . OUTGOING ) ) { if ( r . equals ( n ) ) continue ; Statement st = Statements . relationshipType ( r ) ; if ( st instanceof AN ) { Relationship t = AN . _ . getREF ( r ) ; newREFs . add ( t ) ; } else if ( st instanceof Reference ) { try { <START_BUG> PipedInput in = Evaluator . _ . execute ( pf , r ) ; <END_BUG> for ( Object rr : in ) { if ( rr instanceof Relationship ) { newREFs . add ( ( ( Relationship ) ( rr ) ) ) ; } else System . out . println ( ( "UNHANDLED<seq2seq4repair_space>" + rr ) ) ; } } catch ( IOException e ) { e . printStackTrace ( ) ; } } } } first = false ; System . out . println ( "getEndNode<seq2seq4repair_space>OUTGOING" ) ; getOutgoingReferences ( pf , n . getEndNode ( ) , newREFs ) ; } if ( ( newREFs . size ( ) ) == 0 ) return null ; nextREFs = newREFs ; } } private void getOutgoingReferences ( PFlow pf , Node node , List < Relationship > newREFs ) { } private Relationship searchForHAVE ( final Relationship ref , final String name ) { } private Relationship searchForHAVE ( final Node ref , final String name ) { } public Relationship get ( Node context , final String name ) { } private Relationship getByHave ( final Node context , final String name ) { } private Relationship getByIC ( final Node context , final String name ) { } public Set < Relationship > getByTraversal ( final Relationship underHAVE , final Relationship start_op , final PropertyContainer context , final String name ) { } private Relationship ICresult ( PropertyContainer context , Relationship r ) { } abstract class Searcher implements Evaluator { public Evaluation _evaluate_ ( Path path , Node target , RelationshipType type ) { } } }

Fix:
PipedInput in = Evaluator . _ . execute ( new PFlow ( pf ) , r ) ;